Stop mechanism foe buttonhole sewing machines



AYPLIGATION FILED MAR. 15, 1913.

Patented NOV.3,1914.

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I G. S. HILL.

STOP MEGHANISM FOR BUTTONHOLE SEWING MACHINES.

APPLIG ION FILED MAR. 15, 1913.

1,115,936,: V Patented N0v.3,1914;

2 SHBETS-SHEET 2.

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UNITED sntr isg'rnrnnr OFFICE.

GEORGE s. HILL; or scennrronp, NEW HAMPSHIRE, ASSIGNOR" T0. UNITEJ) snon MACHINERY COMIANY, or" PATERSON, E JEnsEY,- A conPoRA'rIon or NEW JERSEY.

STOP avrnorrnnislii Eon BUTTONHOLE-SEWING MAoHI Es.

. PatentedNov. e, 1914.

Application filed. March 15, 1913f Serial No. 754,487.

tain new and useful Improvements in Step Mechanism for Buttonhole -Sew1ng Ma-- chines; and I do hereby, declare the followingto be a'full, clear,,and exact description of the invention such as willflena'ble others skilled in the art to which it apperi tains to make and use the same.

The. invention relates to a safety device for .buttonhole sewing or. other ma-J chines in which mechanism is provided, for stopping the machine or some mechanism of the machine in a predetermined position.

The object of the invention is to provide -devices which will enable the operator to readily throw out the stoppingidevices when for any reason it is desired to turn the driv-..

ing shaft by hand, and which will insure the return of the shaft and the parts driven thereby to the original stopplng position be 25 1fore' the machine is again operated by power, thus avoiding all danger of getting'the partsaof the machine out of time by thev manual manipulation of the driving shaft.

*"To thisend the invention consists in the features of construction and combinations of parts hereinafter described and referred .to in the claims.

- The invention will be readily understood from an inspection of the accompanying drawings and the following detailed descrlption ofthe mechanism illustrated therein.

In the drawings, F lgure 1 1s a front elevation showing so much of a buttonhole sewing machine as is necessary to-illustra'te the application of the lnvention thereto;

'Fig. 2 is a detail sectional elevation showing the parts in stopping positlon; F 1g. 3 1s a detail plan view showing the means for re ndering the stopping devices inactive 1n its normal position; Fig. 4 is a view similar to.

Fig. 2 showing the position of the parts when the driving shaft has been turned manually through a partial revolution; and

Fig. 5 is adetail plan; view of the parts the position shown in Fig. d.

In the drawings the invention is shown embodied in a buttonhole sewing machine having the construction and mode of operation of the machine fully shown and de-g 3,;and an upper needle et'mounted to recipl, a workclamp 2 which is moved to bring the work vfrorncutting to sewing position, and s fed longitudinally and-laterally during the sewing of a buttonhole, and stitch forming device's comprising an under needle and; looper (not shown-) mo'unte d in. a turret rocate in a: rotary head; the turret and head being rotated in sewing about the end and about the eyeof the buttonholel. The stitch forming mechanism and the mechanism for feeding the-work clamp are driven during the sewing'of the buttonhole from thesew mg shaft 5 through a pulley 6 and clutch member 7 mounted on the shaft. The. clutch member is secured to the shaft while the pulley is mounted to turn freely about the shaft and is moved to engage and disengage the clutch members through devices operated by a vertically movable'rack bar 8 and oscillating sleeve 9. When the pulley is disengaged from the clutch member the shaft 5 and parts driven thereby are automatically stopped in a predetermined position by a stop arm 10 and a coiiperating stop cam-11 formed on the. hub ofth'e clutch member. The stop arm 10 is securedto a vertical rock shaft 12 andis connected with.

a spring 13'which' yieldingly supports the arm in position with the upper end of the v,

shaft 12 against a stop screw 14, and also tends toswing the arm into the path-0f the cam 11; When the pulley is connected'with the clutch member to drive the stitch formmg and clamp feeding mechanism, the stop arniis held .out'of the path ofthe cam 11 against the tension of the spring 13 by a cam 15 which engagesan arm 16 secured to the lower. end of the shaft 12. "When the pu'lley is disengaged from the clutch memher the arm 16 is released by the cam, and the spring 13 tends to swing-the stop arm 10 into active position, and to bring the upper end of a roll- 17 carried by the arm into the path of thecam 11 At 'this't ime the r0111? rid-es along theinclined side-18 i of the cam 11, so that it moves gradually into the path of the cam. i After the clutch pulley has been disengaged from the clutch member, the rotation of the shaft 5 -con-.-

tinues and? the inertiaof. the parts; and the end of the roll. lZ on the stop'arm rides-j determined position, as indicated in Fig. 2.

In the machine shown, the stopping devices an. so arranged that the shaft 5 is brought to rest when the needles of the s'titch forming mechanism are retracted, the

under needle being withdrawn below the work clamp where it is not conveniently accessible to the operator.- In order that the under needle may be rendered conveniently accessible, as for instance when it is to be threaded, it is desirable that provision be made for turning the shaft 5 through at least a partial revolution by hand. Movement of the shaft 5, however, is prevented or resisted bythe stop arm and cam, and means is therefore provided by which the operator may readily render the stopping devices inactive, and the shaft 5 is pro vided with-a knurled head 20 by which it may be manually manipulated. The turning of the shaft5 through a partial or complete revolution after it has been stopped, and before the machine is again started,

' maythrow the mechanisms driven from the shaft 5 out of time with other mechanisms of the machine, and means is accordingly provided for insuring the return of the shaft to its original position.

Inthe construction shown, the means for rendering the stopplng devices inactive to enable the shaft to be turned by hand, and for insuring the return of the shaft to its. original position, comprise a bell crank lever the operating arm 21 of which extends into position "where it may be convenlently reached by the operator, and the other arm 22 ofwhich carries a cam 28 for engaging the end of the stop arm 10 and swinging it into inactive position. The arm 22 of the lever is also provided with a projection 24. which is brought into the path of a stop shoulder 25 formed on a flange 26 of the clutch member 7, when the lever is operated to move the stop arm 10 out of active position. The flange 26 is provided with a recess27mwhich is in position. to receive the projection 24 when the parts are in stopping position, as indicated in Fig. 2. The flange is also provided with a locking surface 28 extending from thejrecess 27 to the stop shoulder 25 which .enga ggs the projection 24 when the shaft 5'is turned from normal stopping position, and locks the projection 24 and bell crank lever in active posi: tion. r

If the operator desires to manipulate the shaft 5 and stitch forming mechanism by hand when the machine is at rest, he swings the bell cranklever from the position indicated in Fig. "2' to the position indicated in Flg. 4. During thismovcment of the lever the cam 23 swings the stop arm 10 out of active position, and the stop projection 24 enters the recess 27. The operator may now turn the shaft 5 forward until the stop shoulder 25 strikes the stop 24, as indicated in Fig. 4:, when further forward movement of the shaft is prevented. The locking surface 28 acting against the end of the projection 24 prevents the return of the bell crank lever to the inactive position indicated in Fig. 2, so long as the shaft is out of normal stopping position. Before the bell crank lever can be returned to inactive position the cam shaft must be returned to the normal stopping position indicated in Fig. 2 when the recess 2? registers with the projection 24% and allowsthe bell crank lever to return to inactive position. The return of the cam shaft and parts driven thereby to the position in which they were stopped by the stopping devices is thus insured. The bell crank lever may be retained in either position against accidental dis lacement by a spring pm 29, the conical on of which is adapted to engage one or the other of two notches formed in the lever.

While it is preferred to employ the specifie construction and arrangement of parts shown and described, in applying the invention to the machine illustrated in the drawings, it will be understood that the invention is notconfined in its application to this machine, and that the construction and arungement of the parts may be varied and modified as may befound desirable or best suited to the construction of the machine in which it is to be embodied.

Having explained the nature and object of the invention,'and specifically described one form of machine in which it may be embodied, what I claim is 1. A machine of the class described, having,in combination adriving shaft, devices for arresting the s aft in a predetermined position, means whereby the operator may render the stopping devices inactive to enable the shaft to be turned by hand, and means for insuring the return'of the shaft to its original position.

2. A machine of the class described, having, in combinatioma driving shaft, stoppingdevices for arresting the shaft in a predetermined position, means under the control of the operator for rendering the stopping devices inactive and for limiting the movement which may be given to the shaft by hand.

3. A. machine of the class described, having, in combination, a shaft, stopping devices for arresting the shaft in apredetermined position, means under the control of the operator for rendering the stopping de vices inactive and for limiting the movement which may be given to the shaft by hand, and devices for preventing the return of said means toinactive osition while the shaft is out of its originaFstopped position.

4. A machine'of the class described, having, in combination, a shaft, stoppin devices for arresting the shaft in a pr etermined position including a, stop arm, a manually operated cam for moving the stop arm out of active position, and supplemental stopping devices rendered active by the' movement of the cam.

GEORGE 's. HILL. Witnesses:

CHESTER E. Roonns, RUTH E. WARD.

Copies of this natent may be obtained for live cents each, by addressing the Commissioner of Patents,

i Washington, D. C. 

